This invention relates to a system and apparatus to be embodied in and in connection with a turbine drive unit which affords the ultimate in safety in its use. It will be particularly described with reference to a turbine driven starter. However, this is only for purpose of illustration and not by way of limitation, either as to its application or the form of its embodiment.
Industry has had the utmost of concern for injury to person and/or property in the use of turbine drive units. Overspeed of such a device beyond its designed limits can readily be caused to occur by misoperation, a simple inadvertent or careless act or omission on the part of an operator or an unforeseeable malfunction of the apparatus to which it is applied. Any one of these undesirable occurrences can produce disastrous consequences. A most undesirable consequence can be the self-destruction of the unit or component parts thereof,. In the use of a turbine driven starter for an engine, for example, such self-destruction can and has occurred with such explosive force as to cause fragmentation of the starter housing with resultant danger, damage and/or injury to adjacent persons and/or property.
Much time and money has been spent in efforts to find solutions to this problem, with varying degrees of success. It is believed that the best solution heretofore conceived is currently found in the Series 52A Turbine Driven Air Starter of Tech Development Inc. of Dayton, Ohio, U.S.A. The construction and arrangement of the turbine drive of this apparatus dictates a "benign" failure of the unit should the rotor of the turbine starter, for one reason or another, reach a speed of rotation beyond its designed limit.
The present invention provides an advantageous, solution to the above described problem which when embodied within a turbine driven unit, such as a starter, provides it with a very simple but positively operating control system which automatically functions as the turbine rotor reaches a predetermined speed of rotation to induce a reduction in or a substantially complete cutoff of the flow of air or other gaseous fluid being delivered to the rotor to furnish its motive power.
The inventor is not aware of any prior art which exhibits his improvements in turbine drive units, particularly in starters, which are exemplified in the present disclosure.